Elastomeric railroad crossing structure

ABSTRACT

A railroad crossing structure which includes a plurality of elongated center section pad members and a plurality of elongated outside field section pad members. The pad members are of width substantially the same as the center spacing between adjacent cross ties which are fastened to and span adjacent cross ties. Each pad member comprises an elongated arch member having horizontal flanges extending along each side of the arch member which is adapted for respective connection to adjacent cross ties with the longitudinal axis of the arch member disposed substantially parallel to the axes of the ties. A plurality of tension support rods are connected in chordal position across the arch of the arch member and along the flanges which are adapted to support the arch member against spreading with consequent vertical deflection when a vertical load is imposed downwardly on the arch member. A rectangular elastomeric pad body corresponding in shape to the length and width of the arch member and flanges is bonded to the upper surfaces and the arch member.

United States Patent Hein et al.

[ Feb. 18, 1975 Primary ExaminerRobert S. Ward, Jr. AssistantExaminerRichard A. Bertsch [5 7] ABSTRACT A railroad crossing structurewhich includes a plurality of elongated center section pad members and aplurality of elongated outside field section pad members. The padmembers are of width substantially the same as the center spacingbetween adjacent cross ties which are fastened to and span adjacentcross ties. Each pad member comprises an elongated arch member havinghorizontal flanges extending along each side of the arch member which isadapted for respectiveconnection to adjacent cross ties with thelongitudinal axis of the arch member disposed substantially parallel tothe axes of the ties. A plurality of tension support ods' are connectedin chordal position across the arch of the arch member and along theflanges which are adapted to support the arch member against spreadingwith consequent vertical deflection when a vertical load is imposeddownwardly on the arch member. A rectangular elastomeric pad bodycorresponding in' shape to the length and width of the arch member andflanges is bonded to the upper surfaces and the arch member.

28 Claims, 7 Drawing Figures 3 IO 26 (l PATENTEI] FEB] 8 i975 SHEET 10F3 3,866,830 snmzor 5, mm 6 A PATENTED FEB 1 8 I975 H mm m @w PATENTEBFEB] 8IE175 sum I 3 HF ELASTOMERIC RAILROAD CROSSING STRUCTUREBACKGROUND OF THE INVENTION This invention generally pertains tocomposite railroad crossing structures which incorporate elastomericmaterials and more specifically pertains to an improved railroadcrossing structure including a plurality of structural traffic padsadapted to be fastened to adjacent railroad ties to span between theties. Each such unit comprises an elastomeric body incorporating anintegral and substantially rigid arch support member.

It has been long recognized that, where roads, streets and highwayscross railroad tracks, a smooth transition of both railroad and pavementthrough such crossing is highly desirable even at low vehicle speeds andessential at high vehicle speeds for the sake of personal safety and toprevent vehicle and cargo damage. Various metal, concrete, wood andelastomeric structures have been devised in attempting to reduce oreliminate the problem of rough crossings. Of these the elastomeric typesof structures are deemed to be superior for a number of reasons setforth below with respect to the accomplishments attained by the presentinvention.

DESCRIPTION OF THE PRIOR ART SUMMARY OF THE INVENTION The presentinvention provides a smooth railroad crossing structure which will notchip, splinter, crack, spall, corrode or rot.

The present invention also provides a railroad crossing structure whichmay be readily installed without heavy or specialized equipment and withminimum preparation of railroad ties as normally found in place.

The present invention also provides a structure having an improved ratioof weight to resistance to vertical compression.

The structure of the present invention may be provided of individualsections or pads with each section adapted to span and to be fastened totwo adjacent railroad ties whereby a movable hinge relationship isestablished between the ties and such section which will allow arespective tie to deflect or pump slightly, as happens when the loadedwheels of a railway car truck passes over such tie, without looseningthe attachment of the pad section to the tie.

The present invention provides individual pad sections which aresufficiently narrow in width to be installed to closely match the widthof the roadway pavement.

The present invention provides a structure which may be readily adaptedto railroad tracks which are either straight or curved.

LII

The present invention also may be provided with anti-skid groovesdisposed parallel to roadway traffic to produce greater resistance toside skid or fish-tailing of automobile vehicles.

The foregoing and other provisions and advantages are attained in arailroad crossing structure which includes a plurality of elongatedcenter section pad members and a plurality of elongated outside or fieldsection pad members. The pad members are of width substantially the sameas the center spacing between adjacent cross ties. The pads are fastenedto and span adjacent cross ties. Each pad member comprises an elongatedupwardly extendingarch member having horizontal flanges extending alongeach side of the arch member. Each flange is adapted for respectiveconnection to adjacent cross ties with the longitudinal axis of the archmember disposed substantially parallel to the axes of the ties. Aplurality of tension support rods are connected in chordal positionacross the arch of the arch member and along the flanges. The tensionsupport rods are adapted to support the arch member against spreadingwith consequent vertical deflection when a vertical load is imposeddownwardly on the arch member. A rectangular elastomeric pad bodycorresponding in shape to the length and width of the arch member andflanges is bonded to the upper surfaces of the flanges and the archmember. The pad body defines a horizontal traffic supporting surfacedisposed above the arch member and the flanges. The traffic supportingsurface may be provided. with anti-skid grooves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary elevationalcross sectional view taken along the line 1-1 of FIG. 2 showing thecenter section pad of the present invention and portions of the fieldsection pads as installed at a railroad crossing.

FIG. 2 is a plan view of a portion of a railroad crossing as providedwith the crossing structure of the present invention. I

FIG. 3 is an enlarged partly sectional view of the installation asviewed in FIG. 1.

FIG. 4 is a cross sectional view as taken along the line 44 of FIG. 2.

FIG. 5 is an enlarged plan view of a field section pad as shown in FIG.2.

FIG. 6 is an elevational partly sectional view of the field section padshown in FIG. 5.

FIG. 7 is an elevated cross sectional view taken along the line 7-7 ofFIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT The same or functionally similarelements as illustrated in the various views of the drawings aredesignated with the same number.

Referring to FIGS. 1 4, there is shown a railroad crossing structure 10of the present invention. Crossing structure 10 typically includes apair of rails 12 supported on a plurality of cross ties 14. The rails 12are fixed to each of the ties 14 by means of spikes l6 driven throughholes in tie plates 18 whereby the offset heads of the spikes 16 serveto grip the sole flange of each rail into fixed relation against eachtie plate.

Mounted between adjacent cross ties l4 and between the rails 12are'plurality of elastomeric center section traffic pads 20. Pads 20will be later described more 3 fully in view of the structural detailshown in FIGS. 3 and 4.

As also shown in FIGS. 1 and 2, outside the rails 12 and betweenadjacent cross ties 14, there are mounted a plurality of elastomericfield section traffic pads 22. The pads 22 will be later described morefully with reference to the structural detail shown in FIGS. -7.

Each of the center section traffic pads 20 is seen in FIGS. 14 to begenerally rectangular in external configuration as viewed from the top,the sides and the ends. As best seen in FIGS. 3 and 4, each traffic pad20 is a composite structure generally comprising an elastomeric body 24which is molded to substantially a rectangular external shape and moldedin bonded relation to and about a supporting arch member 26. The curveof the arch member 26 terminates on each side with a horizontallyextending support flange 28.

Vertical holes are provided through the body 24 and flanges 28, throughwhich drive spikes or screws 30 may be driven into the ties 14 to fastenthe pad 20 securely to adjacent ties 14. The arch member 26 spans thespace between the ties 14 with the longitudinal axis of the arch memberdisposed substantially parallel to the longitudinal axes of the ties14.-

A plurality of tension support bolts or rods 32 are connected in tensionacross a chord of arch member 26 immediately above flanges 28 as shownin FIGS. 2 and 3. These tension support members may be carriage bolts,threaded tie rods or the like as shown and are preferably installedafter the elastomer of body 24 has been molded and cured into shape andin bonded relation about arch member 26 as shown. The purpose of thetension support rods 32 is to stiffen arch member 26 by preventing anytendency of flanges 28 to spread apart when a vertical load is impresseddown on traffic pad 20 and arch support member 26.

The top of traffic pad member 20 is a generally flat surface 34 in whichmay be molded anti-skid grooves 36 as shown. Such grooves 36 arepreferably molded longitudinally along the surface 34 which is thedirection of automobile traffic along the pavement and across thecrossing structure as installed.

As shown in FIG. 3 the ends of the elastomeric body 24 terminate in adownwardly extending apron 38 having a water run off lip 39 extendingout from its lower end. The length of the traffic pad is provided toclosely fit between the rails 12 whereby the lip 40 is deflected in bythe head of rail 12 as the pad 20 is installed. The lip 40 springs backinto forceful contact with the web of rail 12 when the pad 20 is seated.

As shown in Hg. 4 the width of the elastomeric body 20 is providedapproximately the same as the centerline spacing between the cross ties14. When installed as shown any bulge as caused by loading of thetraffic pad 20 near to its edge will bring the sides of the pad 20 intoforce transmitting contact with its adjacent pad. Thus, when the pads 20are installed in close proximity as shown, a mutual reinforcing and loadbearing relationship is established.

As shown in FIG. 3 the holes provided for fastening spikes 30 may besealed from water and detritus by means of plugs 40, shown in dashedlines.

As also shown in FIGS. 2 and 3, a plurality of flexure cavities or holes42 may be provided in the elastomeric body 24 at the thicker sections ofrubber along the sides of arch member 26. The reasons for provision ofthese cavities include: the cavities give room for flexure of theelastomer under loading and the cavities reduce the overall weight andamount of elastomer used in the traffic pad 20.

When the crossing structure 10 is installed as a curving rather thanstraight section of track, the ends of the traffic pads 20 are installedmore closely together on the inside of the curve than the outside or bydrawing the arch member 26 closer together by means of tension rods 32on the inside of the track curve. As can readily be seen, the relativespacing between adjacent cross ties will be so small as to be negligibleeven on sharply curved tracks.

As can be seen with reference to FIGS. 3 and 4 all the surfaces of thearch member 26 and the flanges 28 are covered with a layer of elastomerwhich is bonded to the metal. Though the elastomer serves no structuralpurpose when provided as such a layer it does serve to protect themetallic elements against corrosion.

FIGS. 1 and 2 depict the flanges 28 of traffic pad 20 supported inspaced relation above the cross ties 14 by an elastomeric pad termed aspacer or filler pad 44. Filler pad 44 may be provided of nearly anymaterial capable of supporting automotive loading but is preferablyprovided of an elastomer which may be reinforced with fiber or metal asknown in the art. The reason for the provision of filler pad 44 is thatthe traffic pad 20 is normally provided of sufficiently low height so asto be horizontally even with the tops of light weight, i.e., shortheight, rails and the filler pads 44 then provide increased height fortraffic pad 20 when installed with heavier and taller rails.

The field (outside) section traffic pad 22 is shown in FIGS. 57. As seenby the designated numbers, much of the construction of the field sectiontraffic pad 22 is the same as the center section traffic pad 20. As withtraffic pad 20, the pad 22 is provided with an elastomeric body 24,supported by an arch support member 26. Flanges 28 are provided whichare adapted to be connected to cross ties by means of spikes or screws(not shown). Tension support members 32 are provided as previouslydescribed.

As can be seen, on comparison of FIGS. 1 and 6, the track or rail end ofpad 22 is provided with a solid shoulder 46 of elastomer which isadapted to abutt the head of rail 12 and provide a smooth transitionbetween the top of the rail and the surface 34 of pad 22. The field endof pad 22 is provided with a closure wall 48. The purpose of the closurewall 48 is to prevent entry of detritus under arch member 26. Also, whenthe crossing structure 10 has been installed as shown in FIG. 2, thecombined closures 48 on the field side of the crossing can serve as aform for pouring concrete or for tamping asphalt for the pavement (notshown) adjacent to the crossing.

When desired the ends of the arch member 26 may be rolled, crimped orbeveled inwardly to some extent to provide a greater thickness ofelastomer at the beginning of the supporting function of arch support 26within the traffic pad 20 and/or 22. Such a bevel is indicated in dashedlines at 50 in FIG. 3.

The preferred material for elastomeric body 24 is neoprene, selected forits superior ozone and weathering resistance. Other weather resistantmaterials may be provided, however, such as certain grades of butylrubbers, ethylene polypropylene rubbers, polysulfide rubbers, siliconerubbers and the like and dictated by effectiveness vs price. A lessexpensive filler material may be used as desired. Elastomeric body 24preferably is provided of hardness in the range of about 5070 durometer,for example.

The foregoing description and drawings will suggest other embodimentsand variations to those skilled in the art, all of which are intended tobe included in the spirit of the invention as herein set forth.

That being claimed is:

1. An elastomeric railroad crossing pad member comprising:

A. an elongated arch member having an upwardly extending arch andincluding horizontal flanges extending from each side of said arch,

B. said arch member being of width substantially the same as the centerspacing of adjacent railroad ties,

C. said arch member being adapted for respective connection through saidflanges to adjacent railroad ties with the longitudinal axis of saidarch member disposed substantially parallel to the axes of said railroadties,

D. a plurality of tension support means connected in chordal relationacross the arch of said arch member and along the tops of said flanges,and

E. an elastomeric pad body defining a horizontal upper surface andbonded to the upper surfaces of said arch and said flanges.

2. The pad member of claim 1 wherein said tension support means comprisecarriage bolts connected across said arch.

3. The pad member of claim 1 wherein said tension support means comprisetie rods connected across said arch.

4. The pad member of claim 1 wherein said elastomeric pad body isneoprene.

5. The pad member of claim 1 wherein said elastomeric pad body is of50-70 durometer hardness.

6. The pad member of claim 1 wherein grooves are defined in alongitudinal direction along said upper surface.

7. The pad member of claim 1 further including filler pads of selectedthickness adapted to be disposed between said flanges and said railroadties.

8. The pad member of claim 1 wherein the ends of said arch are beveledinwardly.

9. A railroad crossing structure including a plurality of elastomericcenter section pad members and a plurality of elastomeric field sectionpad members with each pad member of said pad members comprising:

A. an elongated arch member having an upwardly extending arch andincluding horizontal flanges extending from each side of said arch;

B. said arch member being of width substantially the same as the centerspacing of adjacent railroad ties;

C. said arch member being respectively connected through said flanges toadjacent railroad ties with the longitudinal axis of said arch memberdisposed substantially parallel to the axes of said railroad ties;

D. a plurality of tension support means connected in chordal relationacross the arch of said arch member;

E. said tension support means being adapted to support said arch againstspreading responsive to imposition of a vertical load downwardly on saidarch member;

F. an elastomeric pad body defining a horizontal upper surface andbonded to the upper surfaces of said arch and said flanges; and i G. thearrangement being such that a mutual reinforcing and vertical loadbearing relationship is established by adjacent said pad members.

10. The structure of claim 9 wherein said tension support means comprisecarriage bolts connected across said arch.

l l. The structure of claim 9 wherein said tension support meanscomprise tie rods-connected across said arch.

12. The structure of claim 9 wherein said elastomeric pad body isneoprene.

13. The structure of claim 9 wherein said elastomeric pad body is of50-70 durometer hardness.

14. The structure of claim 9 wherein grooves are defined in alongitudinal direction along said upper surface.

15. The structure of claim 9 further including filler pads of selectedthickness disposed between said flanges and said railroad ties.

16. The crossing structure of claim 9 wherein the ends of said arch arebeveled inwardly.

17. An elastomeric railroad crossing pad member comprising:

A. an elongated arch member having an upwardly extending arch andincluding horizontal flanges extending from each side of said arch,

B. said arch member being adapted for respective connection through saidflanges to adjacent railroad ties with the longitudinal axis of saidarch member disposed substantially parallel to the axes of said railroadties,

C. a plurality of tension support means connected in chordal relationacross the arch of said arch member and along the tops of said flanges.

D. an elastomeric pad body defining a horizontal upper surface andbonded to the upper surfaces of said arch and said flanges, and

E. said pad member being adapted to establish a mutual reinforcing andvertical load bearing relationship with another said pad member when thetwo said pad members are adjacently connected to a common railroad tie.

18. The pad member of claim 17 wherein the ends of said arch are beveledinwardly.

19. The pad member of claim 17 wherein said tension support meanscomprise carriage bolts connected across said arch.

20. The pad member of claim 17 wherein said elastomeric pad body isneoprene.

21. The pad member of claim 17 wherein said elastomeric pad body is of50-70 durometer hardness.

22. The pad member of claim 17 wherein grooves-are defined in alongitudinal directio n along said upper surface.

23. The pad member of claim 17 further including filler pads of selectedthickness disposed between said flanges and said railroad ties.

24. The pad member of claim 17 wherein'sa'idtension support meanscomprise tie rods connected across's'aid arch.

25. The pad member of claim '24 wherein said elastomeric pad body isneoprene.

3,866,830 7 8 26. The pad member of claim 25 wherein grooves are betweensaid flanges and said railroad tie. defined in a longitudinal directionalong said upper surf 28. The pad member of claim 27 wherein saidelastoace.

27. The pad member of claim 26 further including mer'c pad body of 50-70durometer hardness" filler pads of selected thickness adapted to bedisposed 5

1. An elastomeric railroad crossing pad member comprising: A. anelongated arch member having an upwardly extending arch and includinghorizontal flanges extending from each side of said arch, B. said archmember being of width substantially the same as the center spacing ofadjacent railroad ties, C. said arch member being adapted for respectiveconnection through said flanges to adjacent railroad ties with thelongitudinal axis of said arch member disposed substantially parallel tothe axes of said railroad ties, D. a plurality of tension support meansconnected in chordal relation across the arch of said arch member andalong the tops of said flanges, and E. an elastomeric pad body defininga horizontal upper surface and bonded to the upper surfaces of sAid archand said flanges.
 2. The pad member of claim 1 wherein said tensionsupport means comprise carriage bolts connected across said arch.
 3. Thepad member of claim 1 wherein said tension support means comprise tierods connected across said arch.
 4. The pad member of claim 1 whereinsaid elastomeric pad body is neoprene.
 5. The pad member of claim 1wherein said elastomeric pad body is of 50-70 durometer hardness.
 6. Thepad member of claim 1 wherein grooves are defined in a longitudinaldirection along said upper surface.
 7. The pad member of claim 1 furtherincluding filler pads of selected thickness adapted to be disposedbetween said flanges and said railroad ties.
 8. The pad member of claim1 wherein the ends of said arch are beveled inwardly.
 9. A railroadcrossing structure including a plurality of elastomeric center sectionpad members and a plurality of elastomeric field section pad memberswith each pad member of said pad members comprising: A. an elongatedarch member having an upwardly extending arch and including horizontalflanges extending from each side of said arch; B. said arch member beingof width substantially the same as the center spacing of adjacentrailroad ties; C. said arch member being respectively connected throughsaid flanges to adjacent railroad ties with the longitudinal axis ofsaid arch member disposed substantially parallel to the axes of saidrailroad ties; D. a plurality of tension support means connected inchordal relation across the arch of said arch member; E. said tensionsupport means being adapted to support said arch against spreadingresponsive to imposition of a vertical load downwardly on said archmember; F. an elastomeric pad body defining a horizontal upper surfaceand bonded to the upper surfaces of said arch and said flanges; and G.the arrangement being such that a mutual reinforcing and vertical loadbearing relationship is established by adjacent said pad members. 10.The structure of claim 9 wherein said tension support means comprisecarriage bolts connected across said arch.
 11. The structure of claim 9wherein said tension support means comprise tie rods connected acrosssaid arch.
 12. The structure of claim 9 wherein said elastomeric padbody is neoprene.
 13. The structure of claim 9 wherein said elastomericpad body is of 50-70 durometer hardness.
 14. The structure of claim 9wherein grooves are defined in a longitudinal direction along said uppersurface.
 15. The structure of claim 9 further including filler pads ofselected thickness disposed between said flanges and said railroad ties.16. The crossing structure of claim 9 wherein the ends of said arch arebeveled inwardly.
 17. An elastomeric railroad crossing pad membercomprising: A. an elongated arch member having an upwardly extendingarch and including horizontal flanges extending from each side of saidarch, B. said arch member being adapted for respective connectionthrough said flanges to adjacent railroad ties with the longitudinalaxis of said arch member disposed substantially parallel to the axes ofsaid railroad ties, C. a plurality of tension support means connected inchordal relation across the arch of said arch member and along the topsof said flanges. D. an elastomeric pad body defining a horizontal uppersurface and bonded to the upper surfaces of said arch and said flanges,and E. said pad member being adapted to establish a mutual reinforcingand vertical load bearing relationship with another said pad member whenthe two said pad members are adjacently connected to a common railroadtie.
 18. The pad member of claim 17 wherein the ends of said arch arebeveled inwardly.
 19. The pad member of claim 17 wherein said tensionsupport means comprise carriage bolts connected across said arch. 20.The pad member of claim 17 wherein said elastomeric pad body isneoprene.
 21. ThE pad member of claim 17 wherein said elastomeric padbody is of 50-70 durometer hardness.
 22. The pad member of claim 17wherein grooves are defined in a longitudinal direction along said uppersurface.
 23. The pad member of claim 17 further including filler pads ofselected thickness disposed between said flanges and said railroad ties.24. The pad member of claim 17 wherein said tension support meanscomprise tie rods connected across said arch.
 25. The pad member ofclaim 24 wherein said elastomeric pad body is neoprene.
 26. The padmember of claim 25 wherein grooves are defined in a longitudinaldirection along said upper surface.
 27. The pad member of claim 26further including filler pads of selected thickness adapted to bedisposed between said flanges and said railroad tie.
 28. The pad memberof claim 27 wherein said elastomeric pad body is of 50-70 durometerhardness.